1. Field of the Invention
The present invention relates to an image editing apparatus and, more particularly, to an image editing apparatus used, for example, as a film scanner which reads images on a photo film and outputs image signals, and to an image forming apparatus for forming hard copy images corresponding to original images, such as a copying machine and a facsimile apparatus.
2. Description of the Related Art
A film scanner is an apparatus for optically reading original images (hereinafter referred to as "film images") of a photo film (hereinafter referred to as a "film") and outputting image signals, and it is adapted to allow edition of images such as trimming (extraction of a portion of the image), expansion or reduction of the read film image.
Generally, such a film scanner is used combined with a color printer and based on the image signals output from the film scanner, a hard copy image corresponding to the film image is formed.
The process for carrying out trimming in a conventional film scanner is as follows. First, for setting a trimming area, an operator depresses a trimming key on an operation panel with the film image displayed on a screen of a display apparatus. Then, a trimming mode is set and a frame line (hereinafter referred to as "trimming frame") indicating the contour of the trimming area is displayed overlapped with the film image at the central portion of the screen.
Then, the operator changes the setting so that the trimming area is located at a desired position and has a desired size by using a key for designating expansion or reduction of the trimming area and four keys for moving the trimming area upward, downward, to the right and to the left, while monitoring the display on the screen.
Then, when the operator depresses a key for designating output of the image signal, the image signal of the trimmed image is output, and a hard copy image is formed on an output sheet based thereon.
In this manner, in the conventional film scanner, a display for trimming edition including the film image and trimming frame is displayed on a screen of a display apparatus during trimming operation, and the trimming area is determined on this screen.
Therefore, in the prior art, there is no image displayed on the screen indicating the trimmed image only for confirmation, and therefore the operator must depend on the screen on which the whole film image and the trimming frame are displayed in order to confirm whether or not the desired trimming is actually realized by the set trimming area. Since the trimmed image is generally small, it is still more difficult to confirm the state of the images near the periphery of the trimming frame.
Accordingly, even if unnecessary image is left in the trimming frame, the operator may not notice the unnecessary image on the screen and the unnecessary image may be noticed only after the hard copy is done, resulting in an unsuccessful copy or a miscopy.
Films to be read are successively set at the film image reading position of the film scanner. However, the position of setting is not accurate and there is some deviation at every setting of the film.
Therefore, if an area having the same size as the image area of the film image is read, non-image area around the film image may be read because of the positional deviation of the film, which causes image noise. Therefore, in the prior art, an area having little smaller size than the image area is read in consideration of the positional deviation of the film.
For this reason, the input image provided by reading has peripheral portions of the original image area missed, and complete film image could not be input.
A possible solution of this problem is to read an area little larger than the size of the image area so that the whole images in the image area are encompassed, to trim the input image obtained by reading so as to extract only the images in the image area and to remove image noise.
However, in that case, a trimming area having the same size as the image area of the film image must be set and such troublesome operation must be carried out every time the film image is read. Especially when various films of different types (sizes) are to be read, trimming areas having different sizes must be set every time, which operation requires much time and labor.
Conventionally, in a film print apparatus including a film scanner and a page printer, images are automatically magnified (expanded or reduced) corresponding to the size of the sheet at the time of trimming. More specifically, the film print apparatus prints the image (trimmed image) corresponding to the trimming area designated by the operator (user) as large as possible on the sheet.
At this time, magnification in the main scanning direction of reading of the film image is generally implemented by signal processing of repeating or skipping the pixels (a so called electric magnification), while magnification in the subscanning direction is implemented by changing the speed of scanning in reading the film image.
A hard copy image subjected to electric magnification becomes coarse (with lower resolution) as the rate of magnification is increased. If magnification is done by changing the speed of scanning and the speed of scanning is very much different from the speed at the time of equal speed magnification, the hard copy image may be disturbed because of the missynchronization with the page printer.
Therefore, when a very small trimming area is designated, for example, the image quality of the hard copy image may not always what is expected by the operator. However, the operator can not predict the image quality. In such a case, it is desired that the designation of the trimming area is changed to avoid such non-expected printing, or a misprint (miscopy). However, in the prior art, such determination was impossible.
Conventionally, when a trimming area is set, indication suggesting the relation between the size of the trimming area and the size of the output sheet is not provided. Therefore, the trimming area is set without considering the relation with the size of the output sheet.
Therefore, generally, the trimming area and the output sheet are not similar figures. Even if magnification is done such that the length or width of the trimmed image corresponds to the full area allowing printing of the output sheet, the hard copy image formed on the output sheet may not be fully formed on the area allowing printing of the output sheet, causing blank portion in the lengthwise or widthwise direction of the output sheet.
The aspect ratio of a film image is generally 1:15, 1:1.25 or the like which is different from the aspect ratio of 1:41 of generally used output sheets (of standard size), and therefore the aforementioned blank is inevitably generated.